Within the field of metal cutting tools used in groove turning and groove milling operations, cutting inserts removably securable in an insert holder have long since provided a way of performing a cutting operation with a suitably hard material, i.e. cemented carbide, in the vicinity of the cutting edge, where the insert holder, manufactured from a less hard material, is reusable following the disposal of a worn or damaged cutting insert.
This type of cutting tool has been further developed to utilize indexable cutting inserts with an increased number of cutting edges, giving economic benefits from providing an increased number of cutting operations per cutting insert. This type of cutting tool has also been developed to provide a more efficient means of securing the indexable insert to the insert holder.
US 2012/0099935 discloses an indexable cutting insert having two opposing end surfaces, a peripheral side surface, and four cutting portions. The peripheral side surface has two pairs of opposing side surfaces, a first pair including four cutting portion relief surfaces, and a second pair including four cutting portion rake surfaces and four abutment zones. A minimum length dimension between the second pair of opposing side surfaces is coincident with a first plane about which the cutting insert exhibits minor symmetry. For each index position of the cutting insert within an insert holder, three of the four abutment zones are in clamping contact with three reaction zones located on a sidewall surface of the insert holder.
US 2014/0050542 discloses an indexable cutting insert having two opposing main surfaces, a peripheral side surface, and four cutting portions. The peripheral side surface has two pairs of opposing side surfaces, a first pair of short sides including four cutting portion relief surfaces and two positioning notches, and a second pair of long sides including four cutting portion rake surfaces and four locating surfaces. In a plan view of one of the main surfaces, it is clear that a radial plane containing any one of the four cutting edges does not intersect the second pair of long sides. For each index position of the cutting insert within an insert holder, one of the four locating surfaces is supported by a stop surface in an insert pocket of the holder, and one of the two positioning notches engages a positioning pin in the insert pocket.